Concrete mixer



Oct. 10, 1950 A. G. zlcovlcl-l CONCRETE MIXER 3 Sheets-Sheet 1 Filed Oct. 25, 1947 Oct. 10, 1950 A. G. ZICOVICH 2,525,574

CONCRETE MIXER Filed 001;. 25, 1947 3 Sheets-Sheet 2 nm-wme inf/7m; 6: Z/rawk/z Oct. 10, 1950 A. e. ZICOVICH 2,525,574

CONCRETE MIXER Filed Oct. 25, 1947 3 Sheets-Sheet 5 Patented Oct. 10, 1950 CONCRETE MIXER Anthony 'G. Zicovich, San Jose, Calif., assignor of one-half to Arthur W. Caldwell, San Jose,

Calif.

Application October 25, 1947, Serial No. 782,093

This invention relates to concrete mixers and is concerned more particularly with truck-type mixers embodying a stationary mixing tank and means for providing an elevated point of discharge for the concrete.

In the trucking of concrete mixes from a central mixing plant to the construction job the usefulness of the so-called pug-mill concrete mixers embodying a stationary mixing tank has been limited materially by the low level of the discharge mean and by the diificulty of efiecting discharge of the complete batch of concrete from the tank. The instant invention has for its general object the provision of improved concrete mixers of the above type which overcome the above-noted disadvantages and which provide for easy discharge of the complete batch of concrete at a desirable high elevation with tain parts shown in section as indicated by the.

line 3-3 in Figure 2.

Figure 4 is a transverse sectional view of the mixer taken as indicated by the line lt in Figure 1.

Figure 5 is a fragmentary sectional. view of the mixer discharge means taken as indicated by the line 5-5 of Figure 2.

The present invention relates to concrete mixers of the type disclosed in my copending application, Serial No. 771,414, filed August 30, 19 1?. Referring to the drawings, the mixing truck of the present invention includes a truck chassis Ill having a cab I l thereon. A stationary generally cylindrical mixing tank 12 is supported on the chassis l0, and the tank I2 is open at the top in a conventional manner with the top opening being defined by upright flange portions l2a.

Within the tank l2 there is a mixing assembly including a central shaft it upon which a spirally arranged mixing and progressing blade ii is mounted by suitable radial support arms l8 and diagonal bracing arms ilia. The outer edge of the spiral blade il is formed as a resilient extension Ha of. rubber material which efiects a clean sweep around the wall of the tank while yielding to permit passage of rocks in the mix- 13 Claims. (01. 259-169) the tank circumference, but is provided with an additional offset or clearance portion 21 extending upwardly from a discharge opening 28 therein which is located slightly below the shaft l5 and this clearance portion diminishes gradually l to return to the uniform ofiset dimension or the well 26 at the upper portion thereof. The purpose and mode of operation of the clearance portion 2! of the well is referred to hereinafter. Mounted for cooperation with the well 23 is a series of lifting blades 3! carried by respective support arms 32 on the shaft it to travel through the well 26. A diagonally disposed brace 33 ex( tends between each arm 32 and an adjacent lifting blade 3i. Each lifting blade 35 is formed of a main metal blade portion Sta having respective edge portions 3!?) and Iiic of resilient material, such as rubber, detachably clamped thereto. mension substantially equal to the radial offset of the well 26 and extends into the well 26 to engage and sweep around the circumferential wall of the well. It will be noted that one end of the edge portion 31b also sweeps around the end wall 34 of the mixer and is spaced from the edge wall portion 25b of the well at the other end to provide clearance for rocks. The blade edge portion 3| 0 forms an extension of the end of the portion 3|b and also engages the end wall 3% of the mixer. It will be noted that each lifting blade 3| is mounted in an angular relation with respect to both the well 26 and the end wali so that in lifting the material from the bottom of the well up to the discharge opening 28, each blade in effect forms a pocket in the corner space formed between the end wall 34 and the peripheral wall of the well 25. If desired, the lifting blades 3| may alsobe formed with an upwardly opening concavity as considered in traveling from thebottom of the well 26 to the discharge opening 28. 1

The spiral blade H, as itrotates, tends to progress the material into the well 26 where it a The blade edge portion 3|?) is of a radial di is picked up by the bucket-like lifting blades 3| and carried upwardly until it reaches the discharge opening 28. The discharge opening 23 is formed partially in the peripheral Wall of the well 26 and partially in the end wall 34 to form a corner opening above a discharge ramp 36 which closes the bottom of the clearance offset portion 2! and extends radially outward and also rearwardly to overlie the conventional form of discharge chute 37. A right-angle shaped gate 38 slidably mounted in guides 39 normally closes the discharge opening 28 and has an operating lever ti associated therewith for controlling the open and closed positions thereof. Ihe discharge ramp 36 is upwardly convex, as seen in Figure 2, with its high point substantially below the outer wall of the offset clearance portion 27 so that when the gate is closed concrete lifted by the blades 3| will fall back into the tank. With the gate 38 open the concrete will flow out onto the discharge ramp 36 and to the discharge chute 37 in the usual manner.

The provision of the additional offset clearance portion 21 provides for complete discharge of material from each lifting blade 3! as it travels upwardly past the discharge opening 28 and the clearance provided is preferably of an order to enable the largest size rock of the aggregate to free itself during travel of the lifting blade upwardly through the clearance portion. By providing the discharge opening in the corner of the tank, a free flow of material is provided during discharge from the lowest point of the pocket formed between the lifting blade and the walls of the tank. It will be noted that the progressing blade ll cleans the main portion of the tank of concrete and progresses the concrete into the well where it will be available to the lifting blades 31. It will be notedthat a substantial lifting effect will be obtained even in the absence of the resilient edge portions 3!?) and Bic of the lifting blades in the event of breaking or failure of these portions and that only a small amount of concrete would remain in the well even in this abnormal condition of the lifting blades.

While I have shown and described certain preferred embodiments of the invention, it is apparent that the invention is capable of variation and modification from the forms shown so that its scope should be limited only by the scope of the claims appended hereto.

I claim:

1. In a concrete mixer, a frame, a cylindrical mixing tank on said frame, a peripheral well in said tank, a spiral mixing and progressing blade in said tank for conveying concrete therein to said well, a discharge opening communicating with said well at a level between the top and bottom of said tank, a discharge ramp positioned to receive concrete discharged from said well through said discharge opening, said well including a radially offset portion above said ramp, characterized in that each of said series travelling in said well and past said discharge ramp, characterized in that each of said series of blades forms a pocket with the adjacent walls of the tank while moving upwardly through said well to said discharge opening and in that each of said blades is so mounted as to direct material toward said discharge opening when opposite thereto to aid in the discharge of material.

2. In a concrete mixer, a frame, a cylindrical mixing tank on said frame, a peripheral well in ,4 said tank at one end thereof, a spiral mixing and progressing blade in said tank for conveying concrete therein to said well, a discharge opening at an elevated position on said tank at a level between the top and bottom of said tank and at the intersection of said well with the end wall of said tank, a discharge ramp mounted on said tank at said discharge opening for receiving material therefrom, and a series of concrete elevating blades mounted for rotation with said progressing blade and travelling through said well, characterized in that each of said series of blades forms a pocket with the adjacent walls of the tank while moving upwardly through said well to said discharge opening and in that each of said blades is so mounted as to direct material toward said discharge opening when opposite thereto to aid in the discharge of material.

3. In a concrete mixer, a frame, a cylindrical mixing tank on said frame, a peripheral well in said tank at one end thereof, a spiral mixing and progressing blade in said tank for conveying concrete therein to said well, a discharge opening at ii an elevated position on said tank at the intersection of said well with the end wall of said tank, a discharge ramp mounted on said tank at said discharge opening for receiving material therefrom, said well including a radially offset 30 olearance portion above said discharge ramp,

and a series of concrete elevating blades mounted for rotation with said progressing blade and travelling through said well.

In a concrete mixer, a frame, a cylindrical *mixing tank on said frame, a peripheral well in said tank at one end thereof, a spiral mixing and progressing blade in said tank for conveying concrete therein to said well, a discharge opening at an elevated position on said tank at the intersection of said well with the end wall of said tank, a gate for said discharge opening, a discharge ramp mounted on said tank at said discharge opening for receiving material therefrom, said well including a radially offset clearance portion above said discharge ramp, said ramp including an inclined portion underlying the clearance portion of said well to direct material back'into the tank with said discharge opening closed by said gate, and a, series of concrete elevating blades mounted for rotation with said progressing blade and travelling through said well.

5. In a concrete mixer, a frame, a cylindrical mixing tank on said frame, a peripheral well in said tank at one end thereof, a spiral mixing and progressing blade in said tank for conveying concrete therein to said well, a corner discharge opening at an elevated position on said tank at the intersection of said well with the end wall of said tank, an angle-shaped gate for said discharge opening, a discharge ramp mounted on said tank at said discharge opening for receiving material therefrom, and a series of concrete elevating blades mounted for rotation with said progressing blade and travelling through said well.

6. In a concrete mixer, a frame, a cylindrical mixing tank on said frame, a peripheral well in said tank at one end thereof, a spiral mixing and progressing blade in said tank for conveying concrete therein to said well, a corner discharge opening at an elevated position on said tank at the intersection of said well. wi the end wall of said tank, an angle-shaped gate for said discharge opening, a discharge ramp mounted on t said tank at said discharge opening for receiving material therefrom, and a series of concrete elevating blades mounted for rotation with said progressing blade and travelling through said well, each of said elevating blades being mounted for engagement with said well and with the adjacent end wall of said tank.

'7. In a concrete mixer of the type for use in transporting and mixing batches of concrete, a frame, a stationary cylindrical mixing tank on said frame having a peripheral well and a discharge opening at an elevated position in the wall structure of said well at a level between the top and bottom of said tank, and adjacent the rear of said frame, means disposed within the tank for progressing concrete towards said well, and a concrete elevating blade mounted for rotation in said tank to travel through said well and past said discharge opening, said blade being canted to form a pocket with the walls of said well in traveling upwardly to said discharge opening and to direct material toward said opening when opposite thereto.

8. In a concrete mixer of the type for use in transporting and mixing batches of concrete, a frame, a stationary cylindrical mixing tank on said frame having a peripheral well and a discharge Opening at an elevated position in the wall structure of said well at a level between the top and bottom of said tank, and adjacent the rear of said frame, means disposed within the tank for progressing concrete towards said well, and a series of concrete elevating blades mounted for rotation coaxially with said tank to travel through said well and past said discharge opening, each of said blades being canted to form a pocket with the walls of said well in traveling upwardly to said discharge opening and to direct material toward said opening when opposite thereto.

9. In a concrete mixer of the type for use in transporting and mixing batches of concrete, a frame, a stationary cylindrical mixing tank on said frame having a peripheral well and a discharge opening at an elevated position in the wall structure of said well at a level between the top and bottom of said tank, and adjacent the rear of said frame, means disposed within the tank for progressing concrete towards said well, and a series of concrete elevating blades mounted for rotation coaxially with said tank to travel through said well and past said discharge opening, each of said blades having a resilient edge portion extending into said well, and being canted to form a pocket with the walls of said well in traveling upwardly to said discharge opening and to direct material toward said opening when opposite thereto.

10. In a concrete mixer of the type for use in transporting and mixing batches of concrete, a frame, a stationary cylindrical mixing tank on said frame having a peripheral well and a discharge opening at an elevated position in the wall structure of said well adjacent the rear of said frame, a discharge ramp leading from said discharge opening, said .well wall structure including a radially offset portion above said ramp, and a concrete elevating blade mounted for rotation in said tank to travel through said well and past said discharge opening.

11. In a concrete mixer of the type for use in transporting and mixing batches of concrete,

a frame, a cylindrical mixing tank on said frame, a peripheral well in said tank in coaxial relation therewith, a mixing and progressing blade in said tank for moving concrete into said well, a discharge opening at an elevated position on said tank formed in the wall structure of said well, a discharge ramp mounted on said tank at said discharge opening for receiving material therefrom, said Well including a radially offset clearance portion above said discharge ramp, and a concrete elevating blade mounted for rotation Within said tank and travelling through said well.

12. In a concrete mixer, a frame, a cylindrical mixing tank on said frame, a peripheral well in said tank at one end' thereof, a spiral mixing and progressing blade in said tank for conveying concrete therein to said well, a discharge opening at an elevated position on said tank at the intersection of said well with the end wall. of said tank, a discharge ramp mounted on said tank at said discharge opening for receiving material therefrom, said Well including a radially offset clearance portion above said discharge ramp, and a series of concrete elevating blades mounted for rotation with said progressing blade and travelling through said Well in sliding contact with a circumferential wall and an end wall thereof through an arc of movement approaching said discharge opening, characterized in that each of said series of blades is so canted as to form with said walls, while traversing said arc, a pocket having its lowest point at the junction. of said walls.

13. In a concrete mixer, a frame, a cylindrical mixing tank on said frame, a peripheral well in said tank at one end thereof, a spiral mixing and progressing blade in said tank for conveying concrete therein to said well, a discharge opening at an elevated position on said tank at the intersection of said well with the end wall of said tank, a discharge ramp mounted on said tank at said discharge opening for receiving material therefrom, said well including a radially offset clearance portion above said discharge ramp, and a series of concrete elevating blades mounted for rotation with said progressing blade and travelling through said well in sliding contact with a circumferential wall and an end wall thereof through an arc of movement approaching said discharge opening, characterized in that each of said series of blades forms a pocket with said walls while traversing said are and in that each of said blades is so mounted as to slope downwardly toward said discharge opening when opposite thereto to aid in the discharge of material.

ANTHONY G. ZIGOVICI-I.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 812,849 Jaquet Feb. 20, 1906 1,804,386 Agee May 12, 1931 1,902,733 Smestad Mar. 21, 1933 2,047,317 Esslen July 14, 1936 2,082,752 Lewis et al. June 1, 1937 2,168,779 Murray Aug. 8, 1939 

